I know this is a very old thread, but I want to share my experience with the Ibanez V7, V8, V1, V2, and a bunch of DiMarzio pickups. I have two identical 2001 Ibanez RG570 MIJ guitars. Both guitars came with Ibanez V7(neck)/S1(middle)/V8(bridge) pickups, and are setup identically with D'Addario 009-042 strings. The V7 is bright & has tight/reduced lows, it makes the neck position sound similar to the bridge. The V8 has good harmonics & rhythm crunch, but mids are a bit relaxed & highs are somewhat bright for soloing. The S1 is a relatively hot single coil that blends well with tapped humbuckers. I especially like the fact that the S1 can be lowered away from the strings & still retain a good, strong output.
I decided to keep one of the RG570's stock & experiment with different humbuckers in the other.
I tried some DiMarzios...
Bridge: Tone Zone - too muddy.
Bridge: Norton - good bass, fat mids, lacks presence & harmonics.
Bridge: Fred - nice crunch & harmonics, but bass is a bit weak.
Neck: PAF Pro - okay, but could use more power/sustain.
Neck: Breed Neck - bass is too boomy and highs seem a little too aggressive.
Then I tried Ibanez V1 (neck) & V2 (bridge) from a 1990 RG550...
V1 - nice overwound PAF with smooth highs, good definition, & beefy lows.
V2 - warm tone, excellent sustain, harmonics, and dynamics.
In conclusion, my favorite pickups for the RG570 out of all listed above are the Ibanez V2 (bridge) & V1 (neck), because they provide a good variety of sounds & can cover anything from pop to metal. The DiMarzio Fred & PAF Pro combination are good options for rock, pop, and blues. The Ibanez V8 & V7 are good for rhythm players, and would probably work well for leads in darker sounding guitars.
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Here are some details about the pickups I tried...
Ibanez V1 - Alnico, 10.5K Ohms, 1 row of fixed poles & 1 row of slot screws, V1 printed in white on bobbin with fixed poles.
Ibanez V2 - Alnico, 16.4K Ohms, 1 row of fixed poles & 1 row of slot screws, V2 printed in white on bobbin with screws.
Ibanez V7 - Ceramic, 9.5K Ohms, 1 row of fixed poles & 1 row of hex screws, V7 printed in white on bobbin with fixed poles.
Ibanez V8 - Alnico, 16.5K Ohms, 1 row of fixed poles & 1 row of hex screws, V8 printed in white on bobbin with hex screws.
DiMarzio Tone Zone - Alnico 5, 17.3K Ohms, 1 row of fixed poles & 1 row of slot screws.
DiMarzio Norton - Alnico 5, 12.6K Ohms, 1 row of fixed poles & 1 row of slot screws.
DiMarzio Fred - Alnico 5, 10.1K Ohms, 2 rows of hex screws.
DiMarzio PAF Pro - Alnico 5, 8.4K Ohms, 2 rows of hex screws.
(Note: DC resistance values listed above were measured with a high quality Fluke 87 DMM)